Matching newlines in JavaScript

Just a quick note: the . character in a JavaScript regular expression will never match a newline character. If you want to match any character including newlines you can use the [\s\S] character class instead, which means “any character that’s either whitespace or not whitespace”.

This differs from both Python and Perl, where regular expression flags can be used to alter the behaviour of the . character (re.DOTALL and /s respectively).